Looking at the tyres it seems unlikely that it’s been ridden before those photos were taken. On the downtube, it looks like flecks of paint are still on the cabling.
I would think that it is probably damaged in transit, and you are responsible for the packing. We all know you can’t trust a courier as far as you can chuck a bike in a box.
I still think the suggested repair cost is a bit high, and the price of the paint smells off, but it’s three smallish scratches to the frame and some black on the fork. Ignoring the chain suck.
I suggest trying to come to a better agreement with the buyer.